New Illuminated Keyboard Design Could Mean Even Thinner MacBooks

A newly released Apple patent application could make future MacBooks thinner. The patent for an “in-plane keyboard illumination system,” was published today, April 25, by the U.S. Patent and Trademark Office.
According to Apple's application, this product uses “alternative keyboard lighting arrangements that utilize illumination sources in the same plane as the keyboard keys, with the light therefrom being delivered to illuminate the keys by way of light pipes located within or alongside a webbed structure that runs between the keys.”
They add:

Although the keys have the appearance of being backlit similar to traditional illuminated keyboards, the illumination source is actually located along at least one side of and within the same plane as the pattern of keys, rather than beneath the keys. The keyboard can thus be made thinner in such arrangements where the illumination source does not need to be located beneath the keys.

This type of keyboard is said to be usable on a personal device, laptop, or similar device.
Apple credits Peter Mahowald, Patrick Kessler, and Harold Welch as the inventors of this patent application which was first filed in December.